(1) Field of the Invention
The present invention relates to a liquid crystal display and, more particularly, to a projection type liquid crystal display, that is, a liquid crystal display having the function of correcting the difference in brightness in the vertical direction of the screen, which is depending on the viewing angle.
(2) Description of the Prior Art
In the liquid crystal display of the prior art, the polarity of the voltages applied to the liquid crystal is inverted each field and in adjacent video signal lines. Moreover, the phenomenon that brightness changes with the viewing direction of the display panel is prevented by changing the display brightness in the vertical scanning direction, i.e., by correcting the so-called "viewing angle characteristics".
Specifically, a corrective signal is generated, for example, by differentiating and integrating the signals whose polarity is inverted every field, and the corrective signal is applied to the liquid crystal of each scanning line.
This concept of the prior art is disclosed in Patent Publications such as U.S. Pat. No. 4,906,984 and Japanese Patent Laid-Open No. 59-220,797 (on Dec. 12, 1984).